The study reviewed in this document examined the effects of a comprehensive teacher induction program for beginning teachers (i.e., teachers new to the profession) on teacher and student outcomes in 17 school districts across 13 states. The program includes mentoring, monthly professional development sessions, study groups with other beginning teachers, and opportunities to observe veteran teachers. From the 17 districts participating in the study, 418 elementary schools with a total of 1,009 beginning teachers were randomly assigned to either an intervention group or a comparison group. In the first year of the study, beginning teachers in the intervention schools received the comprehensive teacher induction program. Beginning teachers in the comparison schools received the standard induction services, if any, provided by their district. In the second year of the study, researchers selected a subset of the original districts to receive a second year of the teacher induction program. In these districts, the schools that were originally assigned to receive the intervention continued to offer the intervention services for a second year to beginning teachers. Study authors assessed the effects of the program on both teacher outcomes (practices, satisfaction, preparation, and retention) and student outcomes (achievement) over a 3-year period. The only analyses that meet WWC standards (with or without reservations) were those examining impacts on teacher retention, and therefore, only impacts on these outcomes are described in this WWC report. Impacts after the first year of the study were based on data from all participating districts, all of which received the intervention during the first year. Impacts after the second and third years of the study were presented separately for districts receiving 1 or 2 years of the intervention. Study authors reported, and the WWC confirmed, that the comprehensive teacher induction program had no statistically significant effects on teacher retention, relative to teachers who received the standard induction services provided by their school. The study is a well-implemented randomized controlled trial that meets WWC evidence standards for assessing impacts on teacher retention for the entire sample at the end of year 1 of the study, and for the subset of districts that received only 1 year of the intervention at the end of years 2 and 3 of the study. The majority of the analyses conducted by this study--including impacts on teacher practices, preparation, satisfaction, and some retention outcomes (year 2 and 3 results for districts receiving 2 years of the intervention), along with all student achievement impact analyses--either do not meet WWC evidence standards or were deemed to be ineligible for review by a content expert. [The following study is the focus of this "Single Study Review": Glazerman, S., Isenberg, E., Dolfin, S., Bleeker, M., Johnson, A., Grider, M., andJacobus, M. (2010). "Impacts of comprehensive teacher induction: Final results from a randomized controlled study (NCEE 2010-4027)." Washington, DC: National Center for Education Evaluation and Regional Assistance, Institute of Education Sciences, U.S. Department of Education.] The following are appended: (1) Study details; (2) Outcome measures for the teacher retention domain; and (3) Study findings for the teacher retention domain. A glossary of terms is included. (Contains 4 endnotes.)